Area Forecast Discussion
Issued by NWS Central Illinois

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FXUS63 KILX 151135
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
635 AM CDT Tue May 15 2018

.SHORT TERM...(Today and tonight)
ISSUED AT 316 AM CDT Tue May 15 2018

08z/3am surface analysis shows nearly stationary frontal boundary
extending from north-central Illinois to Kansas. 30-35kt 850mb
jet oriented from the southern Plains northeastward into Illinois
is interacting with the boundary to trigger widely scattered
convection across the KILX CWA early this morning. Latest radar
imagery shows most of the activity along/north of the I-74
corridor:however, isolated cells are also developing further west
and south. Think storms will become more numerous across the
northern CWA in closer proximity to the front over the next 2-3
hours. As a result, have started the day with 40 PoPs along/north
of a Canton to Minonk line. As the low-level jet undergoes diurnal
weakening, the early morning convection will gradually dissipate
before midday. After that, the focus for renewed storm development
will shift to the southern half of the CWA this afternoon as the
front sinks slowly southward. The last few runs of the HRRR have
indicated scattered storms developing along/ahead of the front
generally south of the I-72 corridor after 19z/2pm. Have therefore
featured 40-50 PoPs south of I-72 this afternoon...with areas
further north drying out. Due to cloud cover and scattered
convection, temperatures will be cooler today than they were
yesterday...with highs ranging from the upper 70s far north around
Galesburg to the upper 80s south of I-70. Showers/thunder will
continue across the south into this evening before dissipating
overnight. Lows will range from the middle 50s from the Peoria
area northward...to the middle 60s south of I-70.

.LONG TERM...(Wednesday through Monday)
ISSUED AT 316 AM CDT Tue May 15 2018

00z May 15 models all suggest front will get pushed further
southward into the Ohio River Valley by the middle and end of the
week. GFS remains too wet north of the front, so have rejected its
solution in favor of the drier ECMWF. As a result, have only
carried low chance PoPs across the SE CWA Wednesday and
Thursday...with dry weather across the board on Friday. Despite
FROPA and resulting N/NE winds, high temperatures will remain
above normal for this of year in the lower to middle 80s.

The next frontal boundary is slated to move into the region over
the weekend, bringing a renewed chance for showers and
thunderstorms...particulary Saturday night into Sunday. Once this
front passes, a return to slightly cooler/drier conditions is
anticipated for Monday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 635 AM CDT Tue May 15 2018

A frontal boundary will push south across the area today and this
will be the weather maker for next 24hrs affecting the TAFs.
Scattered showers will continue at PIA and BMI for a few hours
this morning, but as the front moves south, the chance of more
precip later this afternoon will be quite low...so will just have
VCSH at these two sites this morning. SPI/DEC/CMI will see the
front become active for this afternoon so have included VCTS at
these 3 sites for afternoon ending by 00z. IFR cigs exist at PIA
currently and will keep this as a TEMPO group for few hours, but
should improve later this morning. Rest of sites will see VFR
clouds through the period, starting with mid clouds around
12-15kft followed by CU around 5-6kft this afternoon. Winds will
be variable due to the front moving through the area, but all
sites will see speeds less than 10kts and overall direction being
northerly once the front passes.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten



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